I. Biologically important elements

A. H, C, N, O, P, S
B. Na, Mg, Si, Cl, K, Ca, Mn, Fe, Co, Cu, Zn

II. Atoms

A. protons
B. neutrons
C. electrons
D. mass number
E. atomic number

III. Elements

A. Identified by number of protons

IV. Isotopes

A. Atoms of the same element may vary with respect to the number of neutrons
B. deuterium, tritium
C. atomic mass accounts for relative abundance of isotopes of the element (see periodic table)
D. radioisotopes
1. radioactive decay
2. half-life
3. practical uses
a) markers in cells
b) markers for medical diagnosis
c) x-rays
d) treatment of cancer
e) dating rocks and fossils

V. Chemical bonds

A. octet rule
B. nonpolar covalent bonds
C. polar covalent bonds
D. hydrogen bonds
E. ionic bonds
F. van der Waals attractions

VI. Polar and nonpolar substances

A. water
B. oils, fats (hydrocarbons)

VII. Properities of water

A. solid form less dense than liquid form
1. large bodies of water may freeze at surface but remain liquid underneath

B. water is a moderator of temperature

1. ice requires a relatively high amount of heat energy to melt
2. water requires a relatively high amount of heat to evaportate
3. water loses a great deal of heat energy before it becomes ice
4. water has a high heat capacity
5. biologicial implications
a) Earth's realatively stable temperature
b) moderate coastal climates
c) effectiveness of sweating

C. water adheres and coheres

1. water molecules adhere to other polar substances (meniscus)
2. water molecules cohere to each other (surface tension)
3. biological implications
a) walking on water
b) water from roots to leaves

D. water is a good solvent for many substances

1. cells contain a great deal of water
2. most chemical reactions within cells take place in this aqueous environment

VIII. Functional Groups

A. The shape of molecules directly affect their function
1. types of atoms
2. types of bonds
3. specific arrangement of atoms

B. Different molecules that have the same functional group will have some properties in common.

IX. Isomers

A. contain the same number of atoms of the same types, but the atoms are bonded in different ways
B. the different bonding patterns result in different chemical properties
C. glucose and fructose are isomers of each other
D. glucose, fructose, and sucrose
E. structural isomers - vary with respect to covalent arrangement of atoms
F. optical isomers (enantiomers)
1. asymetric carbon - a C bonded to four different atoms or groups of atoms
2. mirror images of each other